> Machine intelligence can be cloned.
This is not entirely correct and we need to get into the weeds to have a proper answer. Most certainly machine's memories are easier to duplicate and replicate than biologicals'. But that's certainly just a distinction of technologies.
We really need to get into the understanding of what the concept of self is. Which I have no answer. But here's the thought experiment to understand the premise. Take your self right now (or any point in the past, but it's easier to be biased that way) and think of a possible major life changing decision you could take. Simulate yourself making different possible decisions (easiest if binary, but it never will be that simple in reality). Project yourself 10 years or so down each path. Are those two people "the same person?" There's certainly arguments for either direction and anyone saying they have a clear well defined answer is fooling you.
Personally, I believe no, they are not. This is because my belief on the self is conditioned on experiences. Without a doubt these people will respond to certain things differently, despite likely having many similar or even identical responses to many other things.
But despite this I still think your argument and concern is valid about ballot-stuffing, especially since my interpretation of self is also conditioned on time and I believe your argument is mostly focused on the instantaneous (or local temporal) cloning. I think this could present a possible solution, in that we define age for machines differently and this is conditioned on the cloning, transfering, pretraining, whatever.
But certainly I have no doubt that what we often take for granted and treat as trivial will reveal its actual complexity. We fool ourselves into thinking simplicity exists, and certainly this is a very useful model, but the truth is that nothing is simple. I think it is best we start to consider and ponder nuances now rather than when we are forced to. After all, the power of humans world modeling and simulation is one of the things that differentiate us from other animals (who many have these same capabilities, but I'm not aware of any that has them remotely to the same degree. Fucking nuance gotta go an make everything so difficult... lol).